Contact-latching arrangement for circuit controlling devices



Sept. 15, 1942. Y J. H. WHEELOCK 2,295,881

CONTACT-LATCHING ARRANGEMENT FOR CIRCUIT CONTROLLING DEVICES Filed Dec. 18, 1939 s Sheets-.-Shee 1 Sept. 15, 1942. J. H. WHEELOCK 2,295,881..

CONTACT-LATCHING ARRANGEMENT FOR CIRCUIT CONTROLLING DEVICES Filed Dec. 18, 1939 s Sheets-Shed? 9 Jagm @111.

Sept. 15, 1942.

J. H. WHEELOCK CONTACT-LATCHINGARRANGEMENT FOR CIRCUIT CONTROLLING DEVICES Filed Dec. 18, 1939 as T53 3 Sheets-Sheet 3 Jim 11. F/zeelach Patented Sept. 15, 1942 CONTACT-LATCHIN CIRCUIT CONT chusetts G ARRANGEMENT FOR ROLLING DEVICES John H. Wheelock, Fitzwilliam, N. H., assignor to Signal Engineering & Manufacturing Company, New York, N. Y., a corporation of Massa- Application December 18, 1939, Serial No. 309,821

10 Claims.

The present invention relates to electrical circuit controlling devices, and has for its object to provide an improved contact-latching arrangement for devices of this character, that is adapted to insure the maintenance of adequate and uniform pressure between relatively movable contacts, after they are once engaged.

The present invention relates particularly to a circuit controller, or relay, of the type employing a movable magnetic member or arma- 1 ture, adapted to carry contacts into and out of engagement with cooperating stationary contacts, in response to energization or deenergization of an operating winding. In circuit controllers of this character, as heretofore constructed, the so-called back contacts that are engaged when the winding is deenergized and the armature down, are held together with a pressure determined either by the weight of the armature itself, or a spring load on the armature tending to hold it down. hand, the so-called front engaged when the winding is armature up, are held together with a pressure determined by the magnetic energized winding.

Obviously, the degree of contact pressure thus obtainable in either case, is definitely limited by the current available to energize the relay under the particular circuit conditions in which it is employed. As a result, increasing the weight of the armature, or the spring loading thereof, in order to obtain greater back contact pressure, will either render the relay sluggish in operation, or increase its pull-up current beyond reasonable limits. For the same reason, an overloaded armature, when pulled up, will not maintain an adequate front contact pressure, particularly when the power source from which the winding is energized is subject to appreciable variations in Voltage.

According to the present invention, there is provided an improved contact latching arrangement for circuit controllers, which cooperates with the contact carrying member so as to positively maintain adequate front or back contact pressure in either position which the member may occupy as a result of the energization or deenerization of its operating winding. Furthermore, the latching arrangement functions in such a manner that the movable contacts are positively locked in engagement with the cooperating front or back stationary contacts at the moment of maximum pressure obtainable as a On the other contacts that are energized and the pull developed by the .5.

Iii)

arm 4 movable with the result of the force developed by the moving armature in pulling up, or dropping back.

The invention further contemplates, in asso ciation with the latching arrangement, the actuation of auxiliary contacts, in response to energization of the operating winding by electrical currents of different values, and the above and other advantageous features of the invention will hereinafter more fully appear from the following description, with reference to the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of a circuit controlling device embodying the invention, with its contact-carrying member in one extreme position.

Fig. 2 is a view similar to Fig. 1, showing the member in an intermediate position.

Fig. 3 is a view similar to Fig. 1, showing the member in a second extreme position.

Fig. 3a illustrates a modification of the device shown in Fig. 1.

Fig. 4 is a view in side elevation of a circuit controlling device provided with a latching arrangement embodying the invention.

Fig. 5 is a view similar to Fig. 4, showing the parts in dilferent positions.

Fig. 6 is a fragmentary sectional view along the line 6-45 of Fig. 5, looking in the direction of the arrows.

Fig. 7 is a view in side elevation of a circuit controlling device provided with a modified latching arrangement embodying the invention.

Figs. 8, 9 and 10 are views in side elevation similar to Fig. 7, but showing the parts of the latching arrangement in different positions.

Fig. 11 is a view in front elevation, of the parts shown in Fig. 10.

Fig. 12 is a fragmentary View showing a circuit control arrangement for the latching elements.

Figs. 13 to 15 inclusive show a still further modification of the latching arrangement.

Like reference characters refer to like parts in the different figures.

Referring first to Fig. 1, the invention is shown, for purposes of illustration, as being embodied in a circuit controller of the front and back contact relay type. The essential elements of such a relay comprise a pivoted armature I that is adapted to be drawn up upon energization of a winding 2, to maintain a contact 3, on an armature I, in engagement with a stationary front contact 5. Upon deenergization of the winding 2, the armature I is free to fall through the intermediate position of Fig. 2, to engage the contact 3 with a stationary back contact 6, as shown in Fig. 3. According to the invention, there is provided a latching arrangement cooperating with the armature I, so as to maintain adequate pressure between the armature contact 3 and the back contact when the armature is in its down position, as in Figs. 4 and 7, or to maintain adequate pressure between the armature contact 3 and the front contact 5 when the armature is in its up position, as shown in Fig. 9.

As best shown in Fig. 4, a latch I is pivoted on a pin 8, so as to move between the arms 9a of a bracket 9 carried by a pole extension ll] of a magnetic core leg H, on which the energizing winding 2 is mounted. The lower end of the latch l is biased toward the free end of the armature l by a spring l2 mounted on a pin [2a, adjustable with respect to the bracket 9, with the upper end bearing on a stop l3, also adjustable on bracket 9. With the armature l in the down position, the end of the latch I engages a latch plate I4 projecting beyond the end of the armature, so that the latter is positively locked against pivotal movement in the direction of the core leg ll. By adjustment of the pins l2a and I3, the pressure of the spring l2 and the position of the latch I can be closely controlled.

A light-weight auxiliary armature I5 is pivoted at It on the upper end of the core leg II, and with the latch I in the position of Fig. 4, a finger H at the lower end of the armature l5 bears lightly on the upper end of the latch 1 above the stop l3. With the winding 2 deenergized, the auxiliary armature l5 is thus biased in a position in which its lower end is slightly offset with respect to the upper end of the pole extension it]. When the winding 2 is energized, the auxiliary armature I5 is attracted toward the pole extension [0, and so moves into the position of Fig. 5, wherein opposed beveled end faces of the armature and pole extension are in substantial parallelism. When this occurs, the finger 11 carried by the armature l5, presses on the upper end of the latch, as indicated by the arrow in Fig. 5, thereby turning the latch l to disengage it from the armature latch plate M. This unlatching occurs very rapidly, so that by the time the winding 2 is fully energized, the armature I is free to pull up into substantial engagement with the core leg ll, thereby moving the armature contact 3 into engagement with the front contact 5, where a front contact is provided, as shown in Fig. 1.

Upon deenergization of the winding 2, the auxiliary armature I5 is released, and the then coinpressed latch spring l2 immediately returns the latch I to the dotted line position of Fig. 5. As the armature l falls, assisted by the pull of a spring [8 connected to the armature, the latch plate [4 snaps past the end of the latch l, which yields and thereupon locks in above the plate M, as shown in Fig. 4, to prevent any turning movement of the armature I. As the armature l moves from the intermediate position of Fig. 2 to the fully down position of Fig. 3, it is obvious that the armature contact 3 will engage the stationary back contact 5 with a sliding movement, due to the inherent flexibility of the contactcarrying arm 4, which gives slightly as the contacts engage, as indicated. Since the armature l is latched positively just as it arrives in the down position of Fig. 4, the armature contact 3 will be positively locked in close engagement with its back contact 6 under considerable pressure,

and there will be no tendency for the contact 3 to rebound after it becomes fully engaged with stationary contact 6.

Furthermore, on a relay employing only a front contact 5, the operation of the latch I will effectively prevent any rebound of the armature as it falls against a stationary stop indicated at IS in Fig. 3a. Thus the latch "I insures the positive locking of the contacts at the moment of greatest pressure obtainable from the energy of the falling armature. In addition, the latching arrangement is extremely effective to prevent accidental contact separation, with resulting arcing, when the relay is used in any location subject to vibration, or where the relay is subject to sudden lurches at different angles, as when in use on shipboard, or on an airplane.

If desired, the arm 4 may be provided with a pair of yieldably mounted contacts 3a cooperating with a pair of stationary back contacts Go, as indicated in Fig. 4. Such a contact structure is fully shown and described in Patent No. 2,082,794, issued June 8, 1937; and it is apparent that the latch 1 will be extremely effective in maintaining the self-alinement and strong pressure that is obtained when these contacts are engaged with each other, upon dropping back of the armature l.

Referring now to Figs. 7 to 11, inclusive, there is shown a modification of the contact-latching arrangement previously described, wherein the contacts carried by the armature, are adapted to be locked in engagement with either the back or front contacts, with provision being made for automatically unlatching the contacts in response to either energization or deenergization of the operating winding. In describing this modified arrangement, the same reference charac- .ters are used to designate similar parts previously described with reference to Figs. 1 to 6, inclusive.

In Fig. '7, the main armature l is shown in its down position, with the winding 2 deenergized. The armature l is maintained in this position by a latch 20 pivoted at 2! on a bracket carried by the relay base, the latch providing a weighted arm 20a, which tends to hold the head of the latch in engagement with the latch plate l4 on the armature l. The latch 20 performs substantially the same function as the latch l, and with the armature I so latched, adequate pressure is maintained between the armature contact 3 and back contact 6, as indicated in dotted lines.

With the parts in the position of Fig. 7, an auxiliary armature 22 pivoted at 23 on the core H, has its extended end portion 22a bearing lightly on the latch 20 below the plate M. In this position, the armature 22 is maintained slightly out of parallelism with core ll, although the weight of the armature 22 is not suificient to shift the latch 20, against the turning force exerted thereon by its unbalanced weighted arm 20a, which serves to maintain the head of the latch in engagement with the plate l4.

When the winding 2 is energized, the auxiliary armature 22 immediately pulls in towards parallelism with the coil H, as indicated in Fig. 8, whereupon the thrust of the portion 22a is sufficient to turn the latch 20 in the direction of the arrow, to disengage its head from the latch plate l4. The release of the latch 20 occurs immediately, so that by the time the core is fully saturated, the main armature l is free to pull up towards the position of Fig. 9. As the armature l moves upwardly, the end of the latch plate l4 bears on the surface of a second latch 24 freely mounted on the same pivot 2| as the latch 20, the latch 24 also providing a weighted arm 24a that tends to turn the latch in the direction of the latch plate I4. Normally, with the winding 2 deenergized as shown in Fig. 7, the upper end of the latch 24 is held away from the plate I4 by a finger 25a provided at the lower end of a second auxiliary armature 25, pivoted at 26 on the core I I, and held away from a pole extension 2'! by a spring 28. However, when the winding 2 is energized, the armature 25 is drawn in to the position of Fig. 8 by the pull of the pole extension 21, so that the latch 24 is free to turn about its pivot 2|, before the armature I starts to pull up.

When the armature I does pull up to the position of Fig. 9, following operation of the auxiliary armatures 22 and 25, in unison, the latch 24 turns about its pivot to engage a notch 29 at its upper end with the armature latch plate It. Therefore, the armature I becomes latched in its upper position, to positively maintain pressure between the armature contact 3 and the front contact 5, as shown in Fig. 9. With the armature I so latched in its upper position, relative movement between the contacts 3 and while the winding 2 remains energized, is effectively prevented.

When the winding 2 is deenergized, the armature 25 is released, thereby permitting the then compressed spring 28 to move the armature 25 to the position of Fig. 10. When this occurs, the latch plate I4 is freed from the notch 29 of the latch 24, whereupon the main armature I drops. Since the other auxiliary armature 22 has previously been released through deenergization of the winding 2, th latch 23 is free to turn, under the unbalanced force of its weighted arm a, so that the head of the latch 2t reengages the latch plate I4 to again maintain the main armature I in its down position, and thereby maintain the back contact pressure, as indicated in Fig. '7.

As described above, the auxiliary armatures 22 and 25, and the main armature I, are adapted to operate in the order named, so that the relay can be used for sequence operation of associated control contacts, if desired. That is to say, each armature can be so designed as regards its weight and balance, as to be responsive to different values of operating current traversing the winding 2, or to different voltages impressed thereon. For example, armature 22 can be caused to pull in in response to one current or voltage value, armature can be caused to pull in at a current or voltage value higher than that required for armature 22, while the main armature I can be caused to pull in at a considerably higher current or voltage value than that required for the auxiliary armatures 2'2 and 25. The above described operation of the armatures 2", 25 and I, in sequence, can be utilized to operate auxiliary contacts, in addition to the main contacts 3, 5 and 6, in accordance with the different positions occupied by the respective latches 2E] and 24, in response to energization or deenergization of the winding 2.

In Fig. 12, there is shown diagrammatically, a circuit arrangement wherein contacts 30 are adapted to be controlled by a bridging member 3| carried by latch 25, while contacts 32 are controlled by a bridging member 33 carried by the other latch 24. Obviously, operation of the latches 20 and 24 by their respective armatures 22 and 25 will bring about desired changes in circuits containing the contacts 30 and 32, in

accordance with difierent values of current or voltage aifecting the winding 2.

Referring now to Figs. 13, 14 and 15, there is shown a further modification of the invention, wherein a single latch 34 is employed to lock the armature I in either its up or down position. The latch 34 is pivoted at 35 on lugs 36, provided by the pole extension It, and the lower end of the latch 34 bears on a latch plate 3? extending from the armature I. A lightweight auxiliary armature 38 is pivoted at 39 on the upper portion of the core leg Na, and with the winding 2 deenergized, a spring 40 holds the armature away from the pole extension III, and so tends to turn the latch 34 in a counterclockwise direction about its pivot 35. iherefore, with the winding 2 deenergized, the lower end of the latch 34 bears on the plate 31, and so locks the armature I in its down position, with the back contacts closely engaged.

When the winding 2 is energized, the resulting attraction of the lower end of the armature 33 to the pole extension Ill immediately turns the latch 34 clockwise into the intermediate position of Fig. 14, wherein its head 36a is in aline- 31. ment with a slot II, provided in the latch plate developed on the armature I, through energization of the winding 2, serves to draw the armature I upwardly, with the latch head 34a passing through the slot 4i. As the plate 31 moves upwardly, the left-hand edge of the slot 4I bearing on a beveled surface of the head 34a, turns the latch slightly against the force exerted by the auxiliary armature, which force is much less than the pull on the main armature, as the latter approaches the core leg II. Therefore, when the armature I reaches its fully attracted position, in which it is substantially horizontal, as showrin Fig. 15, the latch head 34a becomes freed of the slot 4|. As this occurs, the turning force exerted on the upper end of the latch 34 by the still attracted auxiliary armature 38, moves the latch so as to engage a shoulder 42, at the upper side of the head 34a, with the under side of the plate 31. Therefore, the armature I becomes latched in position as it pulls up, to maintain pressure between the engaged front contacts.

Upon deenergization of the winding 2, the then compressed spring 40 moves the auxiliary armature 38 away from the pole extension I0, to turn the latch 34 from the position of Fig. 15, and thereby disengage the shoulder 42 from the edge of the latch plate slot II. The armature I is then free to fall, with the head 34a passing through the slot 4|. As the head 34a clears the slot M, the turning force exerted on the latch 34 by the spring 40 acting through the armature 38, again causes the lower end of the head 34a to engage the upper surface of the plate 31, to thereby maintain the armature I in its down position, with resulting close engagement between the back contacts.

From the foregoing, it is apparent that by the present invention, there is provided an improved contact-latching arrangement for electrical circuit controlling devices of the front and back contact type, whereby the maximum contact pressures obtainable in normal operation are positively maintained in either the energized or deenergized condition of the device.

I claim:

1. A circuit controlling device comprising an operating winding, a magnetic armature carry- When this occurs, the upward pull then i ing a contact movable into engagement with a front stationary contact, in response to energization of said winding, means for locking said armature in position to positively maintain its contact in engagement with said front contact when said winding is energized, and means for unlocking said armature in response to deenergization of said winding, to permit said armature contact to disengage itself from said front contact.

2. A circuit controlling device comprising an operating winding, a magnetic armature carrying a contact movable into engagement with a stationary front contact, in response to energization of said winding, a latch for locking said armature in position to positively maintain its contact in engagement with said front contact when said Winding is energized, and means comprising an auxiliary armature for operating said latch to unlock said main armature, in response to deenergization of said winding.

3. A circuit controlling device comprising an operating winding, a main armature carrying a contact movable into engagement with a stationary contact in response to energization of said winding at a given voltage, a latch for locking said main armature in position to maintain its contact in engagement with said stationary contact, additional contacts operable by said latch, and an auxiliary armature for operating said latch to unlock said main armature and responsive to energization of said winding at a voltage different from the voltage required for operating said main armature and its contact, after being unlocked by prior operation of said latch.

4. A circuit controlling device comprising an operating winding, a main armature carrying a contact movable into engagement with a stationary contact in response to energization of said winding at a given current value, a latch for locking said main armature in position, to maintain its contact in engagement with said stationarv contact, additional contacts operable by said latch and an auxiliary armature for operating said latch to unlock said main armature and responsive to energization of said winding at a current value lower than that required for operating said main armature and its contact, after being unlocked by prior operation of said latch.

5. A circuit controlling device comprising an operating winding, spaced stationary contacts, a magnetic armature carrying a contact movable into engagement with one of said stationary contacts in response to energization of said winding, and movable into engagement with the other of said contacts in response to deenergization of said winding, means for locking said armature in position to positively maintain its contact in engagement with either one or the other of said stationary contacts, depending upon whether said winding is energized or deenergized, and means responsive to the energization or deenergization of said winding for unlocking said armature.

6. A circuit controlling device comprising an operating winding, spaced stationary contacts, a magnetic armature carrying a contact movable into engagement with one of said stationart contacts in response to energization of said winding, and movable into engagement with the other of said contacts in response to deenergiration of said winding, a latch for locking said armature in position to positively maintain its contact in engagement with either one or the nther of said stationary contacts, and means comprising an auxiliary armature movable in response to energization or deenergization of said winding for unlocking said latch in either of its positions.

7. A circuit controlling device comprising an operating winding, spaced stationary front and back contacts, a magnetic armature carrying a contact movable into engagement with said front contact in response to energization of said winding and movable into engagement with said back contact in response to deenergization of said winding, latch means for locking said armature in position to positively maintain its contact in engagement with either said front or back contact, and magnetic means responsive to either energization or deenergization of said winding for operating said latch means to unlock said armature from either of its positions.

8. A circuit controlling device comprising an cperating winding, spaced stationary front and back contacts, a magnetic armature carrying a contact movable into engagement with said front contact in response to energization of said winding and movable into engagement with said back contact in response to deenergization of said winding, a latch for locking said armature in different positions to positively maintain its contact in engagement with either said front or back contact, and an auxiliary armature cooperating with said latch for unlocking said main armature in response to either energization or deenergization of said Winding.

9. A circuit controlling device comprising an operating winding, spaced stationary front and back contacts, a magnetic armature carrying a contact movable into engagement with said front contact in response to energization of said winding and movable into engagement with said back contact in response to deenergization of said winding, latches for locking said armature in different positions to positively maintain its contact in engagement with either said front or back contact, and magnetic means for actuating said latches independently of each other, to unlock said armature in response to either energization or deenergization of said winding.

10. A circuit controlling device comprising an operating winding, spaced stationary front and back contacts, a magnetic armature carrying a contact movable into engagement with said front contact in response to energization of said Winding and movable into engagement with said back contact in response to deenergization of said winding, latches for locking said armature in different positions to positively maintain its contact in engagement with either said front or back contact, and an auxiliary armature for separately actuating said latches, to unlock said main armature in response to either energization or deenergization of said winding.

JOHN H. WHEELOCK.

CERTIFICATE OF C ORRECTI ON.

Patent No. 2,295,881. September 1 19kg.

, JOHN H. WHEELOCK.

It is hereby certified that error appears in the printed specification ofthe above numbered patent requiring correction as follows: Page 3, sec- 0nd column, line 26, strike out "57. when this occurs, the upward pull then" and insert the same after "plate" in line 27; and that the said Letters Patent shouldbe read with this correction therein that the same may oonfom to the record of the case in the Patent Office. I

Signed ma sealed this 20th day of October, A. D. 19LL2.

7 Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 2,295,881. September 1 191m.

JOHN H. mom.

It is hereby certified that error appears in the printed specification ofthe abovenumbered patent requiring correction as follows: Page 5, sec-,

0nd column, line 26, strike out "57. when this occurs, the upward pull then" and insert the same after "plate" in line 27; and that the said Letters Patent should be read with this correction therein that the suamemay conform to the record of the case in the Patent Office.

Signed md sealed this 20th day of October, A. D. 19L 2.

Henry Van Arsdale (Seal) Acting Commissioner ofvPatents. 

